Electric rectifier



Oct. 9, 1934. a w M LDER 1,976,454

ELECTRIC RECTIFIER Filed Nov. 22. 1928 l5 f5 iy. Z. (.5 45 I .74? .16 J% 9%- Patented Oct. 9, 1934 UNITED STATES ELECTRIC RECTIFIER Johannes Gijsbertus Wilhelm Mulder, Eindhoven, Netherlands, assignor to N. V. Philips Gloeilampenfabrieken, Eindhoven, Netherlands, a limited-liability company of the Netherlands Application November 22, 1928, Serial No. 321,213 In the Netherlands January 13, 1928 2 Claims.

The present invention relates to an electric device comprising a rectifier, more particularly to a device provided with a rectifier comprising an incandescent cathode, one or more anodes and a gaseous filling. The invention also relates to a rectifier suitable for use in such a device. Certain features described in the present invention are claimed in my copending divisional application Ser. No. 713,767, filed March 2, 1934.

It is known that the starting voltage of discharge tubes serving for the radiation of light can be reduced by providing electrically conducting members on the outer wall of the tube and by electrically connecting the said members to an electrode.

It was to be expected that such members would also give rise to a reduction of the back ignition voltage. For this reason similar members are not provided in discharge tubes which do not serve for the radiation of light but for the rectification of alternating currents.

I have found that this is incorrect and that on a rectifier there can be provided electrically conducting members which reduce the starting voltage without prejudicially decreasing at the same time the back ignition voltage.

For this purpose, the rectifier in an electric device, according to the invention, comprises one or more electrically conducting members arranged between the cathode and an anode. If these members are arranged outside the rectifier they are electrically connected to the anode while if arranged in the interior of the rectifier, they are connected to the anode via a condenser. The distance from the conducting members to the anodes should preferably be smaller than to the cathode.

The electrically conducting members may be connected through a variable condenser to an anode and, if arranged in the interior of the tube, they may have the shape of a wire or a rod. The electrically conducting members may consist of metal members, preferably of molybdenum, which surround the anodes and in which a contraction or a diaphragm may be provided.

The anodes are preferably arranged in arms having one or more narrowed portions provided between the cathode and the anodes while in that case the electrically conducting members may be located entirely or partly between the cathode and the narrowed portions of the arms.

The invention will be more clearly understood by referring to the accompanying drawing in which:

Figure 1 is a side-view of a rectifier tube in which the conducting members are electrically connected to the anodes and are placed within the arms in which the anodes are located.

Fig. 2 is a side-view of a rectifier tube in which the conducting members electrically connected to the anode are wire-shaped and are located within the arms of the tube.

Fig. 3 is a side-view of a rectifier tube in which the conducting members electrically connected to the anodes, are in the form of metal caps, located within the arms of the tubes.

In all these figures the wall of the discharge tube is indicated by l, the arms of the rectifier by 2, the cathode by 3 and the anodes'by 4.

As shown in Fig. 1 the arms may have narrowed portions arranged between the anode 4 and an auxiliary electrode to be more fully described hereinafter.

In the interior of the discharge tube shown in Figure 1 are arranged electrically conducting members 7 which are connected through condensers 8 to the electrodes 4.

In the mode of execution shown in Figure 2 wireshaped members 9 are located in the arms of the rectifier, said members being connected through variable condensers 10 to the anodes.

Figure 3 shows a mode of realization in which the electrically conducting members are constituted by metal caps, preferably of molybdenum, composed of two parts 11 and 12 and arranged in the interior of the rectifier soas to be insulated from the anodes. At 13 parts 11 and 12 are screwed to each other. Since the caps consist of two parts the introduction of the diaphragm 14 is facilitated. The caps are connected via condensers 15 to the anodes.

What I claim is:

1. An electric device comprising a rectifying tube having an incandescable cathode, a number of anodes, a gaseous filling, and a conducting member in the discharge space between each of the anodes and the cathode and closer to the cathode than are the anodes and electrically connected by way of the sole intermediary of a condenser to the anode.

2. An electric device comprising a rectifying tube provided with arms and having an incandescable cathode and a gaseous filling, a plurality of anodes of which one is located in each of said arms, and. a cylindrical conducting member in each arm and electrically connected to the anode therein by the sole intermediary of a condenser, said conducting members being closer to the cathode than are the anodes and closer to the anodes than to the cathode.

JOHANNES GIJSBERTUS WILHELM MULDER. 

